Myths About Platypus Deaths in Yabby Traps – The Facts

The ongoing issue of wildlife deaths in enclosed yabby traps (such as opera house traps) has led to a lot of community debate and discussion. In hopes of reducing confusion, we’d like to try to clarify the facts surrounding ten common myths about opera house traps.

MYTH 1. There’s no real problem – it’s all been made up by anti-fishing activists and greenies

Unfortunately this problem is a very real one. Numerous responsible persons have reported finding dead platypus, Australian water-rats/rakali or turtles in enclosed yabby traps. In many cases, these incidents have been documented photographically. The peak representative organisations for recreational anglers in Victoria (VRFish) and NSW (Recreational Fishing Association of NSW) both believe that a problem exists and officially support a total ban on use of opera house traps.

MYTH 2. If a platypus can get into a trap, it must be able to get out again

Research by the APC has shown that a platypus consistently tries to escape from an opera house trap by searching for an opening in the trap’s outer surface. It doesn’t look for an exit in the middle of a trap (where the exits are effectively located at the end of inward-pointing funnels) and so doesn’t have any realistic chance of escaping from an opera house trap before drowning (in less than 3 minutes).

MYTH 3. Very few platypus are killed each year – it’s no big deal

Since 2010, 40% of all platypus mortality records reported to the APC have been animals found dead in opera house traps (or home-made versions). In Victoria alone, 11 platypus have been found dead in traps from January to August 2017. The true death toll will of course be much higher, given that most trap-related deaths are (for obvious reasons) never reported.

Similarly, recent community-based studies in Western Australia and Victoria both found that well over 40% of water-rat/rakali mortality records were animals found dead in yabby traps.

MYTH 4. Yabby trapping has been going on for a long time and it’s not getting any worse

Opera house traps have emerged as a major new threat over the past decade or so due to a massive increase in sales of very cheap traps that are imported from overseas. Industry sources indicate that up to 100,000 new opera house traps are sold each year, meaning that huge numbers are now being deployed, both legally and illegally, across Australia.

MYTH 5. Current fishing regulations protect the platypus

Fishing regulations generally restrict the use of enclosed yabby traps to private waters where platypus are not expected to occur, such as farm dams. However, this doesn’t protect the animals because huge numbers of traps are set illegally in platypus waters mainly because of ignorance of the rules. It’s also worth noting that current fishing regulations allow legal usage in places where other air-breathing animals (such as freshwater turtles and water-rats/rakali) can drown in yabby traps.

MYTH 6. Platypus only occur in running water, so there’s no risk when traps are set in dams or lakes

Platypus make use of a wide range of lakes, ponds and dams. The deaths of 5 platypus in the Labertouche Creek system near Melbourne in May actually occurred in a farm dam that was connected to the creek.

MYTH 7. Opera house traps that have a ring fitted around the entrance are safe for platypus

Most opera house traps now have metal rings (typically measuring 7.5 to 10 cm in diameter) fitted around their entrance – unlike older versions that had a flexible cord around the entrance. However, the size of these rings still allows a platypus to enter (see Myth 8), so the rigid ring doesn’t make the trap platypus-safe.

MYTH 8. Platypus can be kept out of traps by making the entrance holes smaller

A platypus’s streamlined shape means that it is very good at getting through small openings. Research has shown that adult females weighing up to about 1 kilogram can move through a rigid 55-millimetre square grid (equating to a 7-centimetre ring in terms of perimeter). Much smaller grids or rings are needed to reliably keep out juvenile platypus (which can weigh as little as 300-400 grams). It’s hard to see how a trap can be designed that will both reliably exclude platypus and still encourage large yabbies to enter. This will be particularly difficult to achieve in Queensland, where red-claw yabbies can grow up to a whopping 600 grams and often achieve weights of 300 grams.

MYTH 9. Traps can be made safe by putting a hole in the roof so wildlife can escape

Well, yes… and no. Extensive research by the APC in Victoria and Dr Tom Grant in NSW has shown that inserting an escape hatch in the roof of an opera house trap does result in a safer trap. However, the findings also indicate that a percentage of the platypus entering modified traps are still likely to drown because they fail to find the exit in time. So, while traps fitted with an escape hatch are less dangerous for wildlife than the current design, it’s wrong to conclude that modified traps are 100% platypus-friendly.

MYTH 10. The opera house trap problem can be solved through public education

Well, yes… and no. Trap-related deaths could undoubtedly be reduced through better public awareness of the risk that enclosed yabby traps pose to wildlife, along with better knowledge about where traps can and can’t be legally set. It would also be a big help if the relevant rules in different states and territories could be brought into line with each other. At the same time, it’s important to recognise that community education is never going to be a complete solution. Some persons (such as children) may not even know that fishing regulations apply, other persons may have heard about the issue but fail to understand the practical detail, and still others may choose to always put their own interests above those of wildlife.

We conclude that banning use of opera house traps (and other enclosed designs) is by far the best option to protect wildlife, especially as safe and perfectly workable alternatives (such as folding or fixed-wall lift nets) are available to catch yabbies.

Molonglo Catchment Group acknowledges the funding assistance provided through the Australian Government's National Landcare Programme Regional Investment Strategy, various ACT Government environment and heritage programs, and various NSW Government programs.